According to a publication in the New England Journal of Medicine,* the Novavax Recombinant Spike protein nanoparticle vaccine [NVX-CoV2373] against SARS-C0V-2 was shown to be safe and immunogenic.

The trial, supervised by the University of Maryland, comprised a randomized, placebo-controlled phase one-two trial involving 131 healthy adults.  In phase one, vaccination consisted of two intramuscular injections 21 days apart.  Eighty three participants received the vaccine with adjuvant and twenty five without adjuvant.  Twenty three participants received placebo.  No serious adverse events were noted other than mild reaction of approximately one to two days duration in participants receiving vaccine with adjuvant.  Addition of adjuvant enhanced immune response and induced T-helper cell response.  The administration of a vaccine with five micrograms adjuvanted nanoparticle vaccine responded with high ELISA assay IgG antibody and neutralization responses that exceeded convalescent serum from symptomatic COVID-19 patients.

The authors concluded that Novavax NVX-CoV2373 was safe and elicited antibody protection.

*Keech, C. et al Phase 1/2 Trial of SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine. The New England Journal of Medicine, September 2, 2020 DOI:10.1056/NEJMoa2026920